Wheat grain storage at moisture milling: Control of protein quality and bakery performance

Abstract

To maintain grain quality and prevent loss, effective storage systems are required. To enable wheat flour of a certain quality to be extracted from grain, stored dry wheat must be humidified prior to milling. With the aim of reducing post-harvest drying stage costs for subsequent grain rehydration, the objective of this study was to optimize the wheat grain storage steps while maintaining the protein quality and baking performance using response surface methodology. A mixed 2 and 3 level design (3 factors) was used to optimize the independent variable (factors) values of grain moisture content (12% and 15%), temperature (14, 26, and 38°C) and storage time (4, 8, and 12-months). The quality of grain, flour, and baking performance were evaluated. It was possible to maintain the gluten protein quality at a low temperature and grain moisture. All of the flour evaluated provided a good baking performance, and there were no significant differences in specific volumes of treatments. Practical applications Dried wheat needs to be humidified before milling, a process named “water tempering” to enable suitable wheat flour extraction. New approaches could be aimed at improving grain quality and optimizing the post-harvest processing, to secure financial and environmental sustainability. One approach to reducing costs and post-harvest optimization is the storage of wheat with an adequate moisture level for use in the milling process, which would reduce costs in the post-harvest drying stage prior to subsequent grain rehydration. Our results showed only minor changes in rheological parameters with the different conditions studied, and these had no influence on the baking performance of samples evaluated.